Manufacture of insecticides



Patented Apr. 8, 1930 UNITED STA TES BATEN'Il OFFICE WALTER HENRY GROOMBRIDGE, OF DEPTFORD, LONDON, ENGLAND, ASSIGNOR '10 ARTHUR J. DICKINSON LIMITED, OF DEPTFOED, LONDON, ENGLAND, A BRITISH COMPANY.

MANUFACTURE OF INSECTICIDES No Drawing.

This invention relates to improvements in and relating to the manufacture of insect-icides and its object is to provide a new, and improved method of manufacturing insecticides particularly but not exclusively intend- A further object is to obtain a silico fluoride in solution by treating an alkaline silico-fiuoride either with or without the addition of extra alkali with a solution of one or more soluble soaps.

Various attempts have been made previously to provide satisfactory insecticides for the purpose stated. Thus for example calcium arsenate has been used, but whilst this substance will destroy the insects, its use is attended with many diadvantages due to its poisonous effect on cattle and human beings. It has also been proposed to use sodium silico-fiuoride but owing to this substance being very diflicult to dissolve in water it has had to be applied by a dusting process in the solid form and this has been found to be both wasteful and troublesome.

The present invention consists of a method of obtaining a silicofiuoride in relatively concentrated aqueous solution, thus providing insecticides in a liquid form, such form for the purpose in view being attended with many advantages.

It has been found that if an alkaline silicofluoride is treated with water in the presence of one or more soluble soaps, preferably alkaline soaps and preferably also in the presence of added free alkali a cloudy solution' is obtained. This solution may be in the form of a colloidal solution or suspension and the word solution wherever used herein is to be taken to include any colloidal solution or suspension of a relatively permanent nature. Simi- Application filed. November 23, 1927. Serial in. 235,393.

larly the word dissolve wherever used herein is to be taken to mean the preparation of a solution as above defined. The above mentioned result may be the consequence of a chemical action having taken place, such'a reaction certainly taking'place" if additional alkali is added to the mixtureas will be hereinafter'described. f v

I prefer to utilize ammoniumusilicofluoride and to mix or treat the samewith caustic soda or other suitable alkali, the resulting material being treated with an aqueous solution of one or more alkaline soaps. It is advisable for'theprocess' of solution to be carried out at a temperature below 30. O.

prefer to start with ammoniumsilicofiuorides in any convenient state. ,Causticsoda or other suitable alkali generally up to. a weight not exceeding two-thirdsthe weight of the silicofluoride employed may if desired be.

used in addition to the silicofluoride and the mixing operation is preferably carried out at temperatures below 30 C.

I do not desire to be limited to any specific proportions of ingredients but so far as my investigations have proceeded I have found that the relative proportions of soap and silicofluoride may vary within fairly wide limits thus for example from equal quantities by weight of dry soap and silicofluoride to about 5 parts of soap to one part of silicofluoride so that my invention may be better understood the following two specific examples are given.

1. lbs. of soft potash soap having a fatty acid content of 40% are'made up to 20 gallons with water. In a separate vessel 20 lbs. of ammonium silicofluoride are dissolved in 15 gallons of water and are treated with a solution of 10 lbs. of caustic soda in 5 gallons of water. The second solution is then gradually added whilst stirring to the first solution, maintaining the temperature meanwhile rather below 30 0., thus obtaining approximately 40 gallons of insecticide.

2. 14 lbs. of ammonium silicofluoride are dissolved in 13 gallons of water and 5 lbs. of caustic soda are added thereto. This mix- ,ture is then added to 2 cwts. of soft potash soap having a fatty acid content of 12.6% and Of the several alkaline silicofluorides, 'I.

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- stances which have mixed in the requisite quantity of water, the temperature being as before maintained below 30 C. and the mixture being finally made up to a bulk of 40 gallons of insecticide.

In either of the above cases the caustic soda can if desired be replaced by other suitable alkali such for example as soda ash or ammonia and the alkali may as stated, either be added to the fluosilicate or to the soa solution and as mentioned above the use 0 added alkali is not essential for the purpose of the invention although I have found that better results are obtained by its use.

-For the purpose of obtaining the best results, it is important for the material which is to exercise insecticidal power to be in the finest ossible state of division or solution and whilst I do not desire to be limited by any theoretical explanation of the chemical or physical chemical reaction taking place according to the invention I believe that the excellent results obtained are due to one or more chemical and/or physical chemical reactions which'cause the formation of colloidal solutions. Thus for example, it is believed that when ammonium silicofluoride is treated with caustic soda, the following reaction takes place to some extent that is to say the first result is the formation of some sodium silicofluoride and free ammonia. The reaction probably proceeds further resulting in the formation of sodium fluoride, ammonium fluoride and silicic acid, according to the equation The result of these two reactions would be the presence of sodium silicofluoride in a very fine state of division either with or without some unchanged ammonium silicofluoride in solution, to other with sodium and ammonium fluoride all bein either in solution or in a very fine state of division the maintenance of which condition would be assisted by the colloidal solutions of silicic acid and soap. The fluorides resulting from this decomposition also have insecticidal properties.

It should be noted that the term alkaline as applied to chemical compounds used herein is intended to mean either one or more compounds either of the alkali metals or one or more ammonium compounds and it should further be noted that the invention is not limited to the use of particular chemical subeen given by we of examples nor to specific proportions an details nor to the precise order in which the steps are carried out all of which details can be varied without vention.

If desired insecticides prepared according to the present invention may of course be departing from the scope of the in- 1. In a method of manufacturing colloidal alkali metal silico fluorides suitable of use as insecticides the step of treating ammonium silicofluoride with alkali metal soaps.

2. In a method of manufacturing a colloidal alkali metal silico fluoride suitable for use as an insecticide the step of treating ammonium silico fluoride with an alkali metal soa 3? In a method of manufacturing colloidal alkali metal silico fluorides suitable for use as insecticides the step of treating ammonium silico fluoride with alkali metal soaps and a caustic alkali.

4. In a method of manufacturing colloidal alkali metal silico fluorides suitable for use as insecticides the step of treating ammonium silico fluoride with alkali metal soaps and caustic alkalis.

5. In a method of manufacturing a colloidal alkali metal silico fluoride suitable for use as an insecticide the step of treating ammonium silico fluoride with an alkali metal soap and a caustic alkali.

6. In a method of manufacturing a colloidal alkali metal silico fluoride suitable for use as an insecticide the step of treating ammonium silico fluoride with an alkali metal soap and caustic alkalis.

7. In a method of manufacturing colloidal alkali metal silico fluorides suitable for use as insecticides the step of treating ammonium silico fluoride with alkali metal soaps at a temperature below 30 C.

8. In a method of manufacturing a colloidal alkali metal silico fluoride suitable for use as an insecticide the step of treating ammonium silico fluoride with an alkali metal soap at a temperature below 30 C.

9. In a method of manufacturing colloidal alkali metal silico fluorides suitable for use as insecticides the step of treating ammonium silico fluoride with alkali metal soaps and a caustic alkali at a temperature below 30 C.

10. In a method 0 manufacturing colloidal alkali metal silico fluorides suitable for use as insecticides the step of treating ammonium silico fluoride with alkali metal soaps and (paustic alkalis at a temperature below 30 11. In a method of manufacturing a colloidal alkali metal silico fluoride suitable for use as an insecticide the step of treating ammonium silico fluoride with an alkali metal soap and a caustic alkali at a temperature below 30 C.

12. In a method of manufacturing a colloidal alkali metal silico fluoride suitable for useas an insecticide the step of treating ammonium silico fluoride with an alkali metal soap and caustic alkalis at a temperature be low 30 C.

13. In an insecticide, a colloidal alkali metal silico fluoride in the presence of an ammonium soap in an aqueous medium.

14. In an insecticide, a colloidal alkali 5 metal silico fluoride in the presence of an ammonium soap and an' aqueous solution of fluorides.

15. In a method of manufacturing colloidal alkali metal silico fluorides, the steps of m adding to 60 parts by Weight of soft potash soap having a fatty acid content of 160% in 200 parts of Water, a solution of 20 parts of ammonium silico fluoride in 150 parts of water, and treating the product with a solution of 101 parts of caustic soda in 50 parts of water, agitating the reagents during mixing and maintaining the temperature below 30 C.

16. In a method of manufacturing colloidal alkali metal silico fluorides the steps of adding 14 parts by weight of ammonium silico fluorides in a solution of 130 parts and 5 parts of caustic soda to 280 parts of soft potash soap having a fatty acid content of 12.6% in water, malntaining the temperature below C. and making up the resulting product to about 3 times the volume of the ammonium silico fluoride solution, the reagents being a 'itated during mixing. 30 In witness w ereof I afiix my signature. WALTER HENRY GROOMBRIDGE. 

